The present disclosure relates to optical thin-film based Integrated Computational Element (ICE) devices and, more particularly, to systems and methods of engineering the optical properties of an optical thin-film based ICE device using ion implantation during fabrication.
In the field of thin-film device fabrication for optical purposes, designs of a multilayered thin-film device may seek specific spectral performances. As each of the layers is formed in a stack, fabrication variability results in a multilayered film that may exhibit an incorrect performance at certain wavelengths, or in certain ranges of wavelengths. Once fabrication of the optical thin-film based ICE device is finished and tested, fabrication errors in the ICE device that are beyond a specified tolerance result in the ICE device being discarded and fabrication of a new ICE device is then required. As can be appreciated, this procedure results in waste of time and materials, in detriment of fabrication cost efficiency.
Some fabrication techniques provide alternatives to modifying the optical properties of the multilayer stack in a thin-film based ICE device in-situ or after it is complete (ex-situ), such as by changing temperature and deposition conditions. These fabrication techniques, however, are hard to control. Other approaches simply add further material layers to the stack for correction, but this has the deleterious effect of increasing cost, thickness, and overall optical density of the ICE device. When an error is detected, a correction typically includes changing the thickness of subsequent material layers to compensate for the spectral mismatch. While this may result in more accurate spectral performance, the resulting layer stack may have an incompatible thickness, or the required correction thickness may not be feasible when a large number of errors accumulate.